Pileus Git - ~andy/gtk/blob - demos/gtk-demo/offscreen_window2.c

   1 /* Offscreen windows/Effects
   2  *
   3  * Offscreen windows can be used to render elements multiple times to achieve
   4  * various effects.
   5  */
   6 #include <gtk/gtk.h>
   7
   8 #define GTK_TYPE_MIRROR_BIN              (gtk_mirror_bin_get_type ())
   9 #define GTK_MIRROR_BIN(obj)              (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBin))
  10 #define GTK_MIRROR_BIN_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
  11 #define GTK_IS_MIRROR_BIN(obj)           (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_MIRROR_BIN))
  12 #define GTK_IS_MIRROR_BIN_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_MIRROR_BIN))
  13 #define GTK_MIRROR_BIN_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_MIRROR_BIN, GtkMirrorBinClass))
  14
  15 typedef struct _GtkMirrorBin   GtkMirrorBin;
  16 typedef struct _GtkMirrorBinClass  GtkMirrorBinClass;
  17
  18 struct _GtkMirrorBin
  19 {
  20   GtkContainer container;
  21
  22   GtkWidget *child;
  23   GdkWindow *offscreen_window;
  24 };
  25
  26 struct _GtkMirrorBinClass
  27 {
  28   GtkContainerClass parent_class;
  29 };
  30
  31 GType      gtk_mirror_bin_get_type  (void) G_GNUC_CONST;
  32 GtkWidget* gtk_mirror_bin_new       (void);
  33
  34 /*** implementation ***/
  35
  36 static void     gtk_mirror_bin_realize       (GtkWidget       *widget);
  37 static void     gtk_mirror_bin_unrealize     (GtkWidget       *widget);
  38 static void     gtk_mirror_bin_get_preferred_width  (GtkWidget *widget,
  39                                                      gint      *minimum,
  40                                                      gint      *natural);
  41 static void     gtk_mirror_bin_get_preferred_height (GtkWidget *widget,
  42                                                      gint      *minimum,
  43                                                      gint      *natural);
  44 static void     gtk_mirror_bin_size_allocate (GtkWidget       *widget,
  45                                                GtkAllocation   *allocation);
  46 static gboolean gtk_mirror_bin_damage        (GtkWidget       *widget,
  47                                                GdkEventExpose  *event);
  48 static gboolean gtk_mirror_bin_draw          (GtkWidget       *widget,
  49                                               cairo_t         *cr);
  50
  51 static void     gtk_mirror_bin_add           (GtkContainer    *container,
  52                                                GtkWidget       *child);
  53 static void     gtk_mirror_bin_remove        (GtkContainer    *container,
  54                                                GtkWidget       *widget);
  55 static void     gtk_mirror_bin_forall        (GtkContainer    *container,
  56                                                gboolean         include_internals,
  57                                                GtkCallback      callback,
  58                                                gpointer         callback_data);
  59 static GType    gtk_mirror_bin_child_type    (GtkContainer    *container);
  60
  61 G_DEFINE_TYPE (GtkMirrorBin, gtk_mirror_bin, GTK_TYPE_CONTAINER);
  62
  63 static void
  64 to_child (GtkMirrorBin *bin,
  65           double         widget_x,
  66           double         widget_y,
  67           double        *x_out,
  68           double        *y_out)
  69 {
  70   *x_out = widget_x;
  71   *y_out = widget_y;
  72 }
  73
  74 static void
  75 to_parent (GtkMirrorBin *bin,
  76            double         offscreen_x,
  77            double         offscreen_y,
  78            double        *x_out,
  79            double        *y_out)
  80 {
  81   *x_out = offscreen_x;
  82   *y_out = offscreen_y;
  83 }
  84
  85 static void
  86 gtk_mirror_bin_class_init (GtkMirrorBinClass *klass)
  87 {
  88   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
  89   GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
  90
  91   widget_class->realize = gtk_mirror_bin_realize;
  92   widget_class->unrealize = gtk_mirror_bin_unrealize;
  93   widget_class->get_preferred_width = gtk_mirror_bin_get_preferred_width;
  94   widget_class->get_preferred_height = gtk_mirror_bin_get_preferred_height;
  95   widget_class->size_allocate = gtk_mirror_bin_size_allocate;
  96   widget_class->draw = gtk_mirror_bin_draw;
  97
  98   g_signal_override_class_closure (g_signal_lookup ("damage-event", GTK_TYPE_WIDGET),
  99                                    GTK_TYPE_MIRROR_BIN,
 100                                    g_cclosure_new (G_CALLBACK (gtk_mirror_bin_damage),
 101                                                    NULL, NULL));
 102
 103   container_class->add = gtk_mirror_bin_add;
 104   container_class->remove = gtk_mirror_bin_remove;
 105   container_class->forall = gtk_mirror_bin_forall;
 106   container_class->child_type = gtk_mirror_bin_child_type;
 107 }
 108
 109 static void
 110 gtk_mirror_bin_init (GtkMirrorBin *bin)
 111 {
 112   gtk_widget_set_has_window (GTK_WIDGET (bin), TRUE);
 113 }
 114
 115 GtkWidget *
 116 gtk_mirror_bin_new (void)
 117 {
 118   return g_object_new (GTK_TYPE_MIRROR_BIN, NULL);
 119 }
 120
 121 static GdkWindow *
 122 pick_offscreen_child (GdkWindow     *offscreen_window,
 123                       double         widget_x,
 124                       double         widget_y,
 125                       GtkMirrorBin *bin)
 126 {
 127  GtkAllocation child_area;
 128  double x, y;
 129
 130  if (bin->child && gtk_widget_get_visible (bin->child))
 131     {
 132       to_child (bin, widget_x, widget_y, &x, &y);
 133
 134       gtk_widget_get_allocation (bin->child, &child_area);
 135
 136       if (x >= 0 && x < child_area.width &&
 137           y >= 0 && y < child_area.height)
 138         return bin->offscreen_window;
 139     }
 140
 141   return NULL;
 142 }
 143
 144 static void
 145 offscreen_window_to_parent (GdkWindow     *offscreen_window,
 146                             double         offscreen_x,
 147                             double         offscreen_y,
 148                             double        *parent_x,
 149                             double        *parent_y,
 150                             GtkMirrorBin *bin)
 151 {
 152   to_parent (bin, offscreen_x, offscreen_y, parent_x, parent_y);
 153 }
 154
 155 static void
 156 offscreen_window_from_parent (GdkWindow     *window,
 157                               double         parent_x,
 158                               double         parent_y,
 159                               double        *offscreen_x,
 160                               double        *offscreen_y,
 161                               GtkMirrorBin *bin)
 162 {
 163   to_child (bin, parent_x, parent_y, offscreen_x, offscreen_y);
 164 }
 165
 166 static void
 167 gtk_mirror_bin_realize (GtkWidget *widget)
 168 {
 169   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 170   GtkAllocation allocation;
 171   GtkStyleContext *context;
 172   GdkWindow *window;
 173   GdkWindowAttr attributes;
 174   gint attributes_mask;
 175   guint border_width;
 176   GtkRequisition child_requisition;
 177
 178   gtk_widget_set_realized (widget, TRUE);
 179
 180   gtk_widget_get_allocation (widget, &allocation);
 181   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 182
 183   attributes.x = allocation.x + border_width;
 184   attributes.y = allocation.y + border_width;
 185   attributes.width = allocation.width - 2 * border_width;
 186   attributes.height = allocation.height - 2 * border_width;
 187   attributes.window_type = GDK_WINDOW_CHILD;
 188   attributes.event_mask = gtk_widget_get_events (widget)
 189                         | GDK_EXPOSURE_MASK
 190                         | GDK_POINTER_MOTION_MASK
 191                         | GDK_BUTTON_PRESS_MASK
 192                         | GDK_BUTTON_RELEASE_MASK
 193                         | GDK_SCROLL_MASK
 194                         | GDK_ENTER_NOTIFY_MASK
 195                         | GDK_LEAVE_NOTIFY_MASK;
 196
 197   attributes.visual = gtk_widget_get_visual (widget);
 198   attributes.wclass = GDK_INPUT_OUTPUT;
 199
 200   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
 201
 202   window = gdk_window_new (gtk_widget_get_parent_window (widget),
 203                            &attributes, attributes_mask);
 204   gtk_widget_set_window (widget, window);
 205   gdk_window_set_user_data (window, widget);
 206   g_signal_connect (window, "pick-embedded-child",
 207                     G_CALLBACK (pick_offscreen_child), bin);
 208
 209   attributes.window_type = GDK_WINDOW_OFFSCREEN;
 210
 211   child_requisition.width = child_requisition.height = 0;
 212   if (bin->child && gtk_widget_get_visible (bin->child))
 213     {
 214       GtkAllocation child_allocation;
 215
 216       gtk_widget_get_allocation (bin->child, &child_allocation);
 217       attributes.width = child_allocation.width;
 218       attributes.height = child_allocation.height;
 219     }
 220   bin->offscreen_window = gdk_window_new (gtk_widget_get_root_window (widget),
 221                                           &attributes, attributes_mask);
 222   gdk_window_set_user_data (bin->offscreen_window, widget);
 223   if (bin->child)
 224     gtk_widget_set_parent_window (bin->child, bin->offscreen_window);
 225   gdk_offscreen_window_set_embedder (bin->offscreen_window, window);
 226   g_signal_connect (bin->offscreen_window, "to-embedder",
 227                     G_CALLBACK (offscreen_window_to_parent), bin);
 228   g_signal_connect (bin->offscreen_window, "from-embedder",
 229                     G_CALLBACK (offscreen_window_from_parent), bin);
 230
 231   context = gtk_widget_get_style_context (widget);
 232   gtk_style_context_set_background (context, window);
 233   gtk_style_context_set_background (context, bin->offscreen_window);
 234   gdk_window_show (bin->offscreen_window);
 235 }
 236
 237 static void
 238 gtk_mirror_bin_unrealize (GtkWidget *widget)
 239 {
 240   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 241
 242   gdk_window_set_user_data (bin->offscreen_window, NULL);
 243   gdk_window_destroy (bin->offscreen_window);
 244   bin->offscreen_window = NULL;
 245
 246   GTK_WIDGET_CLASS (gtk_mirror_bin_parent_class)->unrealize (widget);
 247 }
 248
 249 static GType
 250 gtk_mirror_bin_child_type (GtkContainer *container)
 251 {
 252   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 253
 254   if (bin->child)
 255     return G_TYPE_NONE;
 256
 257   return GTK_TYPE_WIDGET;
 258 }
 259
 260 static void
 261 gtk_mirror_bin_add (GtkContainer *container,
 262                      GtkWidget    *widget)
 263 {
 264   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 265
 266   if (!bin->child)
 267     {
 268       gtk_widget_set_parent_window (widget, bin->offscreen_window);
 269       gtk_widget_set_parent (widget, GTK_WIDGET (bin));
 270       bin->child = widget;
 271     }
 272   else
 273     g_warning ("GtkMirrorBin cannot have more than one child\n");
 274 }
 275
 276 static void
 277 gtk_mirror_bin_remove (GtkContainer *container,
 278                         GtkWidget    *widget)
 279 {
 280   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 281   gboolean was_visible;
 282
 283   was_visible = gtk_widget_get_visible (widget);
 284
 285   if (bin->child == widget)
 286     {
 287       gtk_widget_unparent (widget);
 288
 289       bin->child = NULL;
 290
 291       if (was_visible && gtk_widget_get_visible (GTK_WIDGET (container)))
 292         gtk_widget_queue_resize (GTK_WIDGET (container));
 293     }
 294 }
 295
 296 static void
 297 gtk_mirror_bin_forall (GtkContainer *container,
 298                         gboolean      include_internals,
 299                         GtkCallback   callback,
 300                         gpointer      callback_data)
 301 {
 302   GtkMirrorBin *bin = GTK_MIRROR_BIN (container);
 303
 304   g_return_if_fail (callback != NULL);
 305
 306   if (bin->child)
 307     (*callback) (bin->child, callback_data);
 308 }
 309
 310 static void
 311 gtk_mirror_bin_size_request (GtkWidget      *widget,
 312                               GtkRequisition *requisition)
 313 {
 314   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 315   GtkRequisition child_requisition;
 316   guint border_width;
 317
 318   child_requisition.width = 0;
 319   child_requisition.height = 0;
 320
 321   if (bin->child && gtk_widget_get_visible (bin->child))
 322     gtk_widget_get_preferred_size ( (bin->child),
 323                                &child_requisition, NULL);
 324
 325   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 326   requisition->width = border_width * 2 + child_requisition.width + 10;
 327   requisition->height = border_width * 2 + child_requisition.height * 2 + 10;
 328 }
 329
 330 static void
 331 gtk_mirror_bin_get_preferred_width (GtkWidget *widget,
 332                                     gint      *minimum,
 333                                     gint      *natural)
 334 {
 335   GtkRequisition requisition;
 336
 337   gtk_mirror_bin_size_request (widget, &requisition);
 338
 339   *minimum = *natural = requisition.width;
 340 }
 341
 342 static void
 343 gtk_mirror_bin_get_preferred_height (GtkWidget *widget,
 344                                      gint      *minimum,
 345                                      gint      *natural)
 346 {
 347   GtkRequisition requisition;
 348
 349   gtk_mirror_bin_size_request (widget, &requisition);
 350
 351   *minimum = *natural = requisition.width;
 352 }
 353
 354 static void
 355 gtk_mirror_bin_size_allocate (GtkWidget     *widget,
 356                                GtkAllocation *allocation)
 357 {
 358   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 359   gint w, h;
 360   guint border_width;
 361
 362   gtk_widget_set_allocation (widget, allocation);
 363
 364   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 365
 366   w = allocation->width - border_width * 2;
 367   h = allocation->height - border_width * 2;
 368
 369   if (gtk_widget_get_realized (widget))
 370     gdk_window_move_resize (gtk_widget_get_window (widget),
 371                             allocation->x + border_width,
 372                             allocation->y + border_width,
 373                             w, h);
 374
 375   if (bin->child && gtk_widget_get_visible (bin->child))
 376     {
 377       GtkRequisition child_requisition;
 378       GtkAllocation child_allocation;
 379
 380       gtk_widget_get_preferred_size (bin->child,
 381                                      &child_requisition, NULL);
 382       child_allocation.x = 0;
 383       child_allocation.y = 0;
 384       child_allocation.height = child_requisition.height;
 385       child_allocation.width = child_requisition.width;
 386
 387       if (gtk_widget_get_realized (widget))
 388         gdk_window_move_resize (bin->offscreen_window,
 389                                 allocation->x + border_width,
 390                                 allocation->y + border_width,
 391                                 child_allocation.width, child_allocation.height);
 392       gtk_widget_size_allocate (bin->child, &child_allocation);
 393     }
 394 }
 395
 396 static gboolean
 397 gtk_mirror_bin_damage (GtkWidget      *widget,
 398                         GdkEventExpose *event)
 399 {
 400   gdk_window_invalidate_rect (gtk_widget_get_window (widget),
 401                               NULL, FALSE);
 402
 403   return TRUE;
 404 }
 405
 406 static gboolean
 407 gtk_mirror_bin_draw (GtkWidget *widget,
 408                      cairo_t   *cr)
 409 {
 410   GtkMirrorBin *bin = GTK_MIRROR_BIN (widget);
 411   GdkWindow *window;
 412
 413   window = gtk_widget_get_window (widget);
 414   if (gtk_cairo_should_draw_window (cr, window))
 415     {
 416       cairo_surface_t *surface;
 417       cairo_matrix_t matrix;
 418       cairo_pattern_t *mask;
 419       int height;
 420
 421       if (bin->child && gtk_widget_get_visible (bin->child))
 422         {
 423           surface = gdk_offscreen_window_get_surface (bin->offscreen_window);
 424           height = gdk_window_get_height (bin->offscreen_window);
 425
 426           /* paint the offscreen child */
 427           cairo_set_source_surface (cr, surface, 0, 0);
 428           cairo_paint (cr);
 429
 430           cairo_matrix_init (&matrix, 1.0, 0.0, 0.3, 1.0, 0.0, 0.0);
 431           cairo_matrix_scale (&matrix, 1.0, -1.0);
 432           cairo_matrix_translate (&matrix, -10, - 3 * height - 10);
 433           cairo_transform (cr, &matrix);
 434
 435           cairo_set_source_surface (cr, surface, 0, height);
 436
 437           /* create linear gradient as mask-pattern to fade out the source */
 438           mask = cairo_pattern_create_linear (0.0, height, 0.0, 2*height);
 439           cairo_pattern_add_color_stop_rgba (mask, 0.0,  0.0, 0.0, 0.0, 0.0);
 440           cairo_pattern_add_color_stop_rgba (mask, 0.25, 0.0, 0.0, 0.0, 0.01);
 441           cairo_pattern_add_color_stop_rgba (mask, 0.5,  0.0, 0.0, 0.0, 0.25);
 442           cairo_pattern_add_color_stop_rgba (mask, 0.75, 0.0, 0.0, 0.0, 0.5);
 443           cairo_pattern_add_color_stop_rgba (mask, 1.0,  0.0, 0.0, 0.0, 1.0);
 444
 445           /* paint the reflection */
 446           cairo_mask (cr, mask);
 447
 448           cairo_pattern_destroy (mask);
 449         }
 450     }
 451   else if (gtk_cairo_should_draw_window (cr, bin->offscreen_window))
 452     {
 453       gtk_render_background (gtk_widget_get_style_context (widget),
 454                              cr,
 455                              0, 0,
 456                              gdk_window_get_width (bin->offscreen_window),
 457                              gdk_window_get_height (bin->offscreen_window));
 458
 459       if (bin->child)
 460         gtk_container_propagate_draw (GTK_CONTAINER (widget),
 461                                       bin->child,
 462                                       cr);
 463     }
 464
 465   return FALSE;
 466 }
 467
 468 /*** ***/
 469
 470 static GtkWidget *window = NULL;
 471
 472 GtkWidget *
 473 do_offscreen_window2 (GtkWidget *do_widget)
 474 {
 475   if (!window)
 476     {
 477       GtkWidget *bin, *vbox;
 478       GtkWidget *hbox, *entry, *applybutton, *backbutton;
 479       GtkSizeGroup *group;
 480
 481       window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 482       gtk_window_set_screen (GTK_WINDOW (window),
 483                              gtk_widget_get_screen (do_widget));
 484       gtk_window_set_title (GTK_WINDOW (window), "Effects");
 485
 486       g_signal_connect (window, "destroy",
 487                         G_CALLBACK (gtk_widget_destroyed), &window);
 488
 489       gtk_container_set_border_width (GTK_CONTAINER (window), 10);
 490
 491       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 492
 493       bin = gtk_mirror_bin_new ();
 494
 495       group = gtk_size_group_new (GTK_SIZE_GROUP_VERTICAL);
 496
 497       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
 498       backbutton = gtk_button_new ();
 499       gtk_container_add (GTK_CONTAINER (backbutton),
 500                          gtk_image_new_from_stock (GTK_STOCK_GO_BACK, 4));
 501       gtk_size_group_add_widget (group, backbutton);
 502       entry = gtk_entry_new ();
 503       gtk_size_group_add_widget (group, entry);
 504       applybutton = gtk_button_new ();
 505       gtk_size_group_add_widget (group, applybutton);
 506       gtk_container_add (GTK_CONTAINER (applybutton),
 507                          gtk_image_new_from_stock (GTK_STOCK_APPLY, 4));
 508
 509       gtk_container_add (GTK_CONTAINER (window), vbox);
 510       gtk_box_pack_start (GTK_BOX (vbox), bin, TRUE, TRUE, 0);
 511       gtk_container_add (GTK_CONTAINER (bin), hbox);
 512       gtk_box_pack_start (GTK_BOX (hbox), backbutton, FALSE, FALSE, 0);
 513       gtk_box_pack_start (GTK_BOX (hbox), entry, TRUE, TRUE, 0);
 514       gtk_box_pack_start (GTK_BOX (hbox), applybutton, FALSE, FALSE, 0);
 515     }
 516
 517   if (!gtk_widget_get_visible (window))
 518     gtk_widget_show_all (window);
 519   else
 520     {
 521       gtk_widget_destroy (window);
 522       window = NULL;
 523     }
 524
 525   return window;
 526 }